Method of preventing the liberation of fire-damp.



A; VON GRGLING.

METHOD OF PREVENTING THE LIBEEATION OF FIRE DAMP. APPLICATION FILED MAR.16, 1908.

906,872. Patented Dec. 15,1908

UNITED STATES PATENT OFFIU.

ALBRECHT VQN GRijLING; OF VIENNA, AUSTRIA-HTINGARY.

METHOD OF PREVENTING THE LIBERATION OF FIRE-DAMP.

. To all whom it may concem: i

, Be it known that IXALBRECHT VON GRoL 1N0, SDbJGCt of the Emperor ofAustria-.

ated at a low atmospheric pressure and flow-.

ing from several places combines to produce catastrophic disasters.

The present invention relates to a method having for itsobject toobviate the said drawback and to attain a relatively satisfactorysecurity in the working of mines. For this purpose according to thepresent invention the atmospheric pressure in the mines is alwaysmaintained on the same height notwithstanding the variations of theexterior atmospheric pressure, the mines being closed from the outer airby means of suitable pit closures of'known construction and the actuallyexisting ventilating means (ventilators, air feeding shafts andventilating drifts) being retained. The said maintenance of thestationary air pressure in the mines is effected in such a manner thatthe relation between the quantity of air admitted into the mine in aunit of time by means 'of one, ventilator to the quantity of airexhausted from the mine in the same unit of time by means of a secondventilator is regulated according to the barometric height. In thismanner the gas ressure in the mine can be, controlled wit the barometriclimits or even beyond the same by the differences in the numberofrevolutions of the ventilators.

The working of the ventilators can be actuated by means of a motor ofany desired kind and the controllin of the performed work can beeffected eit or by hand according to the observed barometric heights orautomatically by the variations of the atmospheric pressure.

In order to prevent the escape of fire damp at low barometric height ithas already been proposed to feed fres air into the mine by means of ablast ventilator so that the fire dam is being retained in the mineindepen ently from the alterations of the pres.- sure of the exterioratmosphere. Now according to the present invention the action ofSpecification of Letters Patent. Application filed Mama 16, 1908. Serialm. 421,533.

of the ventilation of the mines.

Patented Dec. 15, 1908.

the blastventilator is supported by means of a suction ventilator, thisarrangement presenting the advantage that by differentiating the workingof the two ventilators the facility is afiorded to produce in theinterior of the i mine quite independently from the condition of theexterior atmosphere pressure of any desired height and consequentlydepressions; this method could absolutely not be produced by means ofone single blast ventilator.

Moreover the em loyment of two ventilating devices of equal output ofwhich each is sufficiently large and powerful to perform by itself ifnecessary the ventilation of the mine presents the important advantageof afi'ording a mutual reserve of absolute safety. This is of particularimportance in consideration of the fact that in the event of explosionoccurring-in the interior of the mine blast ventilators are as a ruledamaged and put out of work so that precisely in the cases of similarincidents the mine remains without ventilation. Furthermore in the abovenamed known system the tight closure of the air admission pit (that isto say in the present instance the pneumatically closed working pit) maybecome damaged for some reason or other. If in such case only one singleblast vventilator is employed the ventilation of the mine may be eitherdamaged or en tirely sto ped. A similar occurrence must of course beavoided under all circumstances and in such cases the suction ventilatorwill automatically perform as a complete reserve organ the ventilationof the mine.

A suitable regulation of the number of revolutions of the ventilatoraffords the possibility to variate at will the air pressure in the mineso that the above mentioned arrangement of blowing ventilators andsuction ventilators can also be employed for the urpose of producing anunderpressure wit in the.

mine and to suck up by means of this under.

ressure the fire damp from the rock as also rom the old filled up worksand to exhaust the same b the admission of fresh air, said operationeing preferably carried out. on non working days. above ground can beconstantly submitte to analysis in order to determine the nature Theprocess of closing or reducing the admission opening of the pits forfresh air in order to exhaust the gases of the mine rock by means of asuction ventilator is already The fire damp escaping known but thismethod afiorded until now the possibility to obtain only most insignificant depressions particularly in the caseof extensive sets of a mine. Onthe other hand this method cannot under any circumstances afford thepossibility of increasing the pressure as compared with the exterioratmospheric pressure whenever this may be needed.

As showing a conventional means whereby a method in accordance with thisinvention can be carried out, reference is had to the accompanyingdrawings wherein Figures 1 and 2 represent diagrams of the arrangementof one ventilator or of two ventilators respectively at the mouth of airshafts. Fig. 3 represents an arrangement for the automatic controllingof the output of a similar ventilator and Fig. 4 shows a form ofexecution of the device employed for closing the pit.

In the arrangement according to Fig. 1 air is forced into the air shaftb by means of a forcing ventilator a while a second air shaft 0 servesfor the escape of waste air. The exhaust opening of the latter is madeof such dimensions as to allow of the flowing ofl of only such quantityof air that corresponds to the quantity of air admitted at b when theventilator is working with normal velocity. This takes place at afavorable exterior atmos heric pressure which in this case will coinci ewith the air pressure in the mine. Whenever the exterior air pressurediminishes the ventilator is made to work more rapidly with greatervelocity, whenever the air pressure in the mine is comparativelyincreased, that is to say it remains the same as before.

In the arrangement according to Fig. 2 air is admitted into the pit I)also by means of a pressure ventilator a, while the waste air isexhausted from the pit c by means of a second ventilator d. In order tomaintain constantly in the mine the samedegree of pressure and to avoidalmost completely any variations of pressure the suction ventilator canbe made to work slower to a suitable extent and the forcing ventilatorcorrespondin ly quicker when the barometer is falling. This controllingof the air ressure in the mines can be efi ected accor ing to theobserved barometric heights by suitably regulating the correspondingdriving machines (electromotors, steam engines etc.) either by hand orby means of an automatic regulating device actuated by the falling orrising of the exterior air pressure itself.

One form of regulating device is illustrated by way of example in Fig.3. In the tube of a mercury barometer g with" opencistern are melted inthe ends of a number of metallic wires 1' within the limits of thepossible variations of the mercury level in the barometer tube; thesewires are arranged in juxtaposed pairs superposed one pair above theother so that the mercury as soon as it has reached a certain level willcome in contact with the corres onding pair of wire ends and willestablish t e metallic contact between the same. The metallic wireslareconnected to an electromagnetic apparatus which comes into action assoon as the circuit is closed; the said apparatus has for its object forinstance to turn a lever by means of which a resistance inserted in theleads of a dynamo that drives the ventilator is put in circuit or out ofcircuit. When the barometer is rising the superposed pairs of metallictrical connection and consequently the corresponding resistances 7c of arheostat h are put into clrcuit or as the case may be out of circuit.When the barometer shows the positionthat is most favorable for the minethat is to say as a rule its highest position all metallic wire ends areelectrically connected with each other; I When the mercury column in thebarometer tube is falling the connection of the successive wire pairsWill be gradually interrupted so that the corresponding resistances willbe successively put into or as the case may be out of circuit. Theelectrical contact may however be established for good and all byconnecting the mercury to a return lead m. The maintenance of a uniformair'pressure in the mine always presu poses that the connection of theinterior 0 the mine with the exterior air can be interrupted by means ofa closing device. This is efi'ected by means ofv pit closures such asare already known. Fig. 4 shows by way of example a similar closing adevice. The top of the it is closed by flap doors p which are raise bythe ascending drawing cage 0 and while the latter is in its uppermostposition the said flap doors p are replaced by the bottom 1' of the cageso that in this manner the closure of the pit mouth is not interruptedfor a single moment. When the ca e is being lowered the aperture isagain 0 osed in consequence of the weight of the flap doors p or by someother mechanical means producing the closure of the fla doors. The smalla ertures and slits that remain open in sim ar closing devices are butof secondary importance for the purpose aimed at.

The admission or exhaust of air by means of ventilators as abovedescribed can be performed according to the particular localcircumstances not only through the ventilator pits and the working pitsbut if required also through the pumping shafts.

What I claim is 1. A method of preventing the liberation of fire damp inmines consisting in maintaining an invariable air pressure ofapredetermmed degree in the mine irrespective of barometric variationsin the air exterior of the mine by regulating the quantity of airadwires '1, are successively brought into elec-.

mitted into the mine in 5 unit of time rela tive of the barometricvariations of the air tively to the quantity of air exhausted fromexterior of the mine. the-mine-in the same unit of time. In testimonywhereof I'have hereunto set 2. A methodof preventing the hberation myhand in presence of two subscribing wit- 5 offire damp in minesconsisting inmaintaining nesses. v

" a stationary air pressure of a predetermined degree by regulating thequantity of air ad- ALBRECHT VON GROLING mitted into the mine in a unitof time rela- Witnesses: tively to the ua'ntity of air exhausted fromJosEF RUBURGH,

10 the mine in t e same unit of time irrespec ROBERT W. HEINGARTNER,

v r v r

